We propose a 5-year randomized controlled trial that targets methadone maintenance treatment (MMT) programs in China. Applying the principles of combination prevention, the proposed intervention (MMT CARE) integrates psychosocial and behavioral components into a pharmacological framework for methadone maintenance. A total of 68 MMT clinics will be randomly selected from four provinces. From each clinic, 6 service providers and 36 clients will be recruited, totaling 408 providers and 2,448 clients in the study. The 68 clinics will be randomized to: 1) a MMT CARE intervention group, or 2) a control group (34 clinics each). Service providers who complete the training will conduct three individual motivational enhancement sessions with clients. Efficacy of the intervention will be evaluated at baseline and at 3, 6, 12, 18, and 24-month follow- ups. The outcomes for service providers will be measured by: 1) improved adherence to MMT protocols; 2) decreased prejudicial attitudes; 3) increased interaction with clients; and 4) increased communications with clients about risk reduction. The outcomes for clients will be measured by: 1) improved treatment adherence/retention; 2) decreased concurrent drug use; 3) increased motivation for behavior change; 4) improved mental health; 5) increased positive support; and 6) reduced HIV risk behaviors. PUBLIC HEALTH RELEVANCE: Injecting drug use is a hidden dimension of the global HIV epidemic. China's methadone maintenance therapy (MMT) program is expanding rapidly to address a critical link between drug abuse and HIV/AIDS. However, it faces multiple challenges, including a high dropout rate, high concurrent drug use, and a gap between clients' needs and service providers' skills. This project uses a combination prevention approach to respond to the urgent need for improved quality of services at clinics, provider-client interactions, and client treatment outcomes. Collected data will form the foundation of an evidence-based intervention that can be delivered to over 700 MMT clinics in China, and will potentially serve as a successful model for harm reduction programs in other countries.